Phys.org July 1, 2021 Based on their previous research work on laser, researchers in China further improved the laser performance of Er:YAP laser crystal by laser-diode side-pumping method. A Er:YAP crystal rod with concave end-faces was used to compensate the thermal lensing effect. They achieved maximum output power of 26.75 W at 250 Hz, and 13.18 W at 1000 Hz. They demonstrated a LD side-pumped and electro-optical Q-switched Er,Pr:YAP laser with emission at 2.7 μm. A giant pulse laser was obtained with pulse energy of 20.5 mJ, pulse width of 61.4 ns, and peak power of 0.33 MW at the […]
Category Archives: Laser
Researchers produce laser pulses with record-breaking intensity
Phys.org May 6, 2021 A team of researchers in South Korea demonstrated laser intensity exceeding 1023W/cm2 with the CoReLS petawatt (PW) laser. After wavefront correction and tight focusing with a two-stage adaptive optical system and an f/1.1 (=300mm) off-axis parabolic mirror, they obtained near diffraction-limited focusing with a spot size of 1.1 µm (FWHM). From the measurement of 80 consecutive laser shots at 0.1 Hz, they achieved a peak intensity of (1.1±0.2)×1023W/cm2, verifying the applicability of the ultrahigh intensity PW laser for ultrahigh intensity laser–matter interactions. From the statistical analysis of the PW laser shots, they identified that the intensity […]
Researchers develop first self-cooling laser made with a silica fiber
Phys.org March 17, 2021 An international team of researchers (USA – Stanford University, University of Illinois, Clemson University, Sweden, Canada) has achieved laser cooling in silica optical fiber with 21-µm diameter core doped with ytterbium and co-doped with aluminum oxide and fluoride ion to increase the critical quenching concentration by a factor of 16. Using a custom slow-light fiber Bragg grating sensor they measured temperature changes up to −50mK. The measured dependencies of the temperature change on the pump power and the pump wavelength were in excellent agreement with predictions from an existing model. To understand how fiber composition, core […]
Order from chaos
EurekAlert November 13, 2020 Current technology in LiDARS bounces the laser beams off moving mirrors, a mechanical method that results in slower scanning speeds and inaccuracies. Researchers in Japan have developed a new beam scanning device utilizing ‘photonic crystals’ whose lattice points can be arranged as nanoscale antennae. They found that by adjusting both position and size resulted in a seemingly random photonic crystal, producing an accurate beam without power loss. They called this a ‘dually modulated photonic crystal’. They showed that the scanner can generate beams in one hundred different directions: a resolution of 10×10. With further refinements, the […]
60-year-old limit to lasers overturned by quantum researchers
Phys.org October 27, 2020 Researchers in 1958 showed theoretically that the coherence of a beam cannot be greater than the square of the number of photons stored in the laser based on the assumptions they made about how energy is added to the laser and how it is released to form the beam. Now according to researchers in Australia the assumptions made sense at the time, and still apply to most lasers today, but they are not required by quantum mechanics. They have shown that the true limit imposed by quantum mechanics is that the coherence cannot be greater than […]
Physicists make electrical nanolasers even smaller
EurekAlert September 16, 2020 An international team of researchers (Russia, UK) has developed a new approach to create electrically driven nanolasers for integrated circuits. In their approach electrical pumping is based on a double heterostructure with a tunneling Schottky contact. Plasmon-polaritons (SPPs) replace photons. The pumping happens across the interface between the plasmonic metal and semiconductor, along which surface SPPs propagate. The pumping approach makes it possible to bring the electrically driven laser to the nanoscale, while retaining its ability to operate at room temperature and the radiation is effectively directed to a photonic or plasmonic waveguide, making the nanolaser […]
New metasurface laser produces world’s first super-chiral light
EurekAlert April 27, 2020 An international team of researchers (South Africa, USA – Harvard University, Singapore) has developed a new laser to produce any desired chiral state of light, with full control over both angular momentum (AM) components of light, the spin (polarisation) and orbital angular momentum (OAM) of light. They designed a new nanometer-sized metasurface made up of many tiny rods of nanomaterial within the laser, which alters the light as it passes through. The light passes through the metasurface many times, receiving a new twist every time it does so resulting in the generation of new forms of […]
All Militaries Are Developing Combat Lasers So They Will Give Short Military Advantages
Next Big Future June 3, 2019 Fourth generation fighters (F-16, F-18) and fifth-generation fighters (F-35, F-22) can be seen by shorter range radar. They only have a 20-30 percent chance of evading new short-range missiles. New 50 kilowatt and 150-kilowatt combat lasers that will be added to fighters in the next few years will provide extra defenses to hinder missiles. Combat Lasers could increase the survivability of both stealth and non-stealth fighters and force more missiles to be used to overcome defenses. The US Air Force LANCE laser program will use fiber-optic cables to merge beams to reach tens of […]
Physicists propose perfect material for lasers
Eurekalert May 8, 2019 In Weyl semimetals charge carriers behave the way electrons and positrons do in particle accelerators. Researchers in Russia have shown that reactions forbidden for elementary particles can also be forbidden in the crystalline materials known as Weyl semimetals. Specifically, this applies to the forbidden reaction of mutual particle-antiparticle annihilation without light emission. This property suggests that a Weyl semimetal could be the perfect gain medium for lasers. The team gauged the lifetime of an electron-hole pair in a Weyl semimetal to be about 10 nanoseconds which is much longer than in conventional materials used in laser […]
Lasers make magnets behave like fluids
Science Daily April 18, 2019 When a magnet is hit with a short enough laser pulse the spins within a magnet will no longer point just up or down, but in all different directions canceling out the metal’s magnetic properties. Using mathematical modeling, numerical simulations and experiments an international team of researchers (USA – University of Colorado, NIST, SLAC, Temple University, UK, Sweden, U, Italy, Germany, China, Japan, Belgium) has shown that the spins behaved like a superfluid 3 picoseconds after a laser pulse hits and then form small clusters with the same orientation like “droplets” in which the spins […]